We propose to set up an experimental model combining an isolated liver perfusion apparatus interfaced with a mass spectrometer (MS). The interface between the perfusate and the mass spectrometer will be a semipermeable membrane allowing the diffusion of volatile or volatilizable compounds. This dual apparatus will be used to study in real time the metabolism of short-chain alcohols (methanol, ethanol, propanol) singly and in combination. The mass spectrometer's microprocessor will be programmed for the quasi simultaneous assays of the alcohols and of their metabolites (aldehydes, acids, and CO2). After the completion of the initial feasibility study, the model will serve as a tool for investigation aimed at alleviating the effects of methanol poisoning. We shall follow strategies aimed at blocking methanol oxidation and accelerating formate catabolism. With this study, we hope to demonstrate the usefulness of this combined apparatus for investigating the hepatic metabolism of drugs and xenobiotics which are either volatile or lead to volatile metabolites.